Externally fired combined cycle gas turbine

ABSTRACT

An externally fired gas turbine system according to the present invention has a compressor for compressing ambient air and producing compressed air, an air heat exchanger for heating the compressed air to produce heated compressed air, a turbine for expanding the heated compressed air to produce heat depleted expanded air, and a generator connected to the turbine for generating electricity. According to the present invention, the system also includes combustible products producing apparatus for processing fuel to produce combustible products that include combustible gases and an external combustion chamber for burning the combustible products and transferring heat to the air heat exchanger and producing heat depleted combustion products. The system also includes a closed Rankine cycle steam power plant having a water heat exchanger for vaporizing water and producing steam using heat contained in the heat depleted combustion products. The power plant further includes a steam turbine for expanding the steam producing power and expanded steam, and a steam condenser for condensing the expanded steam producing condensate that is returned to the water heat exchanger.

This application is a division of application Ser. No. 08/594,476, filedJan. 31, 1996, now U.S. Pat. No. 5,687,570.

FIELD OF THE INVENTION

This invention relates to externally fired combined cycle gas turbinesystems which are sometimes referred to as EFGT Systems.

BACKGROUND OF THE INVENTION

Externally fired gas turbine/combined cycle systems have been describedin the literature for a number of years. Such systems include acompressor for compressing ambient air, an indirect contact heatexchanger in which combustible products, e.g., gas and/or fuel vapors,hereinafter referred to as “combustible gases”, are burned to heat thecompressed air, and a turbine in which the heated compressed air isexpanded driving a generator that produces electricity. Heat containedin the turbine exhaust is used to vaporize water that is converted intosteam in a separate water-based, closed Rankine cycle power plant, thesteam being expanded in a steam turbine in the power plant for driving agenerator that produces additional electricity.

EFGT systems have been proposed for use with low calorific, uncleangaseous fuels as well as with hot gaseous fuels. Solid fuels are moredifficult to incorporate into EFGT systems because of the problemsassociated with ash and noxious gases produced during the combustionprocess. It is therefore an object of the present invention to provide anew and improved externally energized gas turbine system such as anexternally fired combined cycle gas turbine system which is capable ofusing solid fuels without many of the usual attendant problemsassociated with burning such fuel in a combined cycle gas turbinesystem.

BRIEF DESCRIPTION OF THE INVENTION

An externally energized gas turbine system such as an externally firedgas turbine system according to the present invention has a compressorfor compressing ambient air and producing compressed air, an air heatexchanger for heating the compressed air to produce heated compressedair, a turbine for expanding the heated compressed air to produceexpanded air, and a generator connected to the turbine for generatingelectricity. According to the present invention, the system alsopreferably includes what is termed “combustible products producingapparatus” for processing fuel to produce gas and/or fuel vaporcollectively referred to hereinafter as “combustible gases”, and anexternal combustion chamber for burning the combustible gases andtransferring heat to the compressed air flowing through the air heatexchanger and producing heat depleted combustion products. The systemalso preferably includes a closed Rankine cycle steam power plant havinga water heat exchanger for vaporizing water and producing steam usingheat contained in the gaseous heat depleted combustion products. Thepower plant further includes a steam turbine for expanding the steamthereby producing power, and from which expanded steam exits, and asteam condenser for condensing the expanded steam producing condensatethat is returned to the water heat exchanger.

In one embodiment of the invention, the water heat exchanger includes apreheater heated by the expanded air for heating the condensate andproducing preheated water, and a vaporizer heated by the heat depletedcombustion products for vaporizing the preheated water thereby producingsteam for the turbine of the power plant.

In a preferred form of the invention, the combustible products producingapparatus includes a pyrolyzer for processing oil shale and producingcombustible gases and a carbonaceous residue, and an air furnace forcombusting the organic material remaining in the carbonaceous residuethereby producing hot flue gases and ash in the form of hot particulate.Means are provided for returning hot ash to the pyrolyzer. In thisinstance, the combustible gases produced by the pyrolyzer and the hotflue gases produced by the air furnace, together with solid particulatematter, constitute the combustible products produced by the processingof the oil shale by the combustible products producing apparatus.

In another embodiment of the invention, the water heat exchangerincludes a superheater heated by the flue gases for superheating steamproduced by the vaporizer. In another embodiment of the invention, thewater heat exchanger includes a preheater heated by both the heatdepleted combustion products and the expanded air (for heating thecondensate thereby producing preheated water), and a vaporizer heated bythe flue gases for vaporizing the preheated water.

In a further embodiment of the invention, the water heat exchangerincludes a vaporizer heated by both the heat depleted combustionproducts and the expanded air for converting the condensate into steam.In such case, a second water-based, closed loop Rankine cycle powerplant may be provided. The second power plant has a second water heatexchanger for vaporizing water and producing steam using heat containedin the flue gases produced by the gas producing apparatus, and a secondsteam turbine for expanding the steam and producing power and expandedsteam. The second power plant also includes a second steam condenser forcondensing the expanded steam exiting the steam turbine and producingcondensate which is returned to the second water heat exchanger.

In a still further embodiment, heat depleted combustion products andexpanded air heat an organic fluid in an organic fluid vaporizerproducing organic vapor for operating an organic vapor turbine. In suchcase, the flue gases produced by the combustible products producingapparatus heat water in a water heat exchanger for vaporizing the waterand producing steam for operating a steam turbine.

The organic vapor is supplied to the organic vapor turbine for producingpower. Expanded organic vapor exits from the organic vapor turbine andis supplied to a condenser for producing organic fluid condensate. Steamproduced in the water heat exchanger is supplied to the steam turbinefor producing power. Expanded steam exhausted from the steam turbine issupplied to a steam condenser for producing steam condensate. In thisembodiment, the expanded steam supplied to the steam condenser is cooledby organic fluid condensate and the resultant steam condensate issupplied to the water heat exchanger. Organic fluid condensate suppliedto the steam condenser is thus preheated and then supplied to theorganic fluid vaporizer. A second Rankine cycle organic fluid powerplant is also included in this embodiment, the organic fluid beingvaporized by heat extracted using an interstage cooler associated withthe air compressor of the gas turbine. In the second Rankine cycleorganic fluid power plant, organic vapor produced by cooling theinterstage cooler is supplied to a second organic vapor turbine forproducing power. Expanded organic vapor exhausted from the secondorganic vapor turbine is supplied to a condenser for producing organicfluid condensate which is supplied by a circulation pump to theinterstage cooler.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention are described by way of examplewith reference to the accompanying drawings wherein:

FIG. 1 is a block diagram of the present invention showing the preferredform of the combustible products producing apparatus and one embodimentof a water heat exchanger that is part of a water-based, closed Rankinecycle power plant;

FIG. 1A is a modification of the steam condenser shown in the powerplant of FIG. 1;

FIG. 2 is a block diagram of another embodiment of water heateraccording to the present invention;

FIG. 3 is a block diagram of a further embodiment of a water heatexchanger according to the present invention;

FIG. 4 is a block diagram of a further embodiment of a water heateraccording to the present invention;

FIG. 5 is a block diagram of a further embodiment of a water heateraccording to the present invention;

FIGS. 5A and 5B are modifications of the compressor-turbine arrangementshown in FIG. 5;

FIG. 6 is a block diagram of a further embodiment of the invention;

FIG. 7 is a block diagram of a further embodiment of the invention;

FIG. 8 is a block diagram of a further embodiment of the invention;

FIG. 9 is a block diagram showing a power plant into which a furtherembodiment of the invention has been incorporated; and

FIG. 9A is an embodiment of an organic vapor turbine to be incorporatedin the power plant shown in FIG. 9.

DETAILED DESCRIPTION

Referring now to the drawings, reference numeral 10 designates anexternally fired combined cycle gas turbine system according to thepresent invention. System 10 includes combustible products producingapparatus 16 (hereinafter, and in the drawings, referred to as “gasproducing apparatus”), external combustion chamber 12, gas turbinesystem 15, and water-based, closed Rankine cycle power plant 36. Gasturbine system 15 includes compressor 11 for compressing ambient air andproducing compressed air, indirect air heat exchanger 30 by which thecompressed air is heated to produce heated compressed air, and airturbine 13 directly connected to and driving compressor 11 and generator14. The heated compressed air expands in turbine 13 thereby driving thegenerator and producing electricity. Expanded air is exhausted from theturbine through exhaust line 13A. These components of turbine 15 areconventional and no further description is believed necessary.

Gas producing apparatus 16 processes fuel to produce combustible gasesin line 18 and hot flue gases in line 19. In the preferred form of theinvention, the gas producing apparatus includes pyrolyzer 20 forreceiving crushed oil shale from dryer 21 and producing combustiblegases in line 18 and carbonaceous residue in line 22. Apparatus 16 alsoincludes air furnace 23 for combusting, in the presence of excess air,the organic material remaining in the carbonaceous residue produced bythe pyrolyzer. Air furnace 23 produces at its output a combination ofhot particulate or ash and hot flue gases which are applied to separator24. The separator serves to separate the flue gases from the hot ash,the finer portion of which is delivered by line 25 to pyrolyzer 20 tosustain its operation. The coarser portion of the hot ash is removed.The hot flue gases, together with some fine ash remaining in the fluegases, are supplied to line 19 which applies the hot gases and theremaining particulate ash, to dryer 21 for the purpose of drying the oilshale before the latter is applied to the pyrolyzer.

Alternatively, the hot gases and fine particulate ash, or other matterstill present together with the flue gases, first of all can be appliedto heat exchanger 26 for extracting heat therefrom and heating, forexample, a working fluid. In such case, heated or preheated workingfluid then can be supplied to a water boiler such as boiler 44, or otherboiler such as a waste heat boiler that uses, for example, an organicfluid like boiler 52 or a suitable boiler for organic turbine 48. In afurther alternative arrangement, a portion of the hot flue gases and theremaining fine particulate ash or matter may be supplied directly todryer 21. The other portion of the hot flue gases and remaining fineparticulate ash or matter may be supplied first to heat exchanger 26 andthen to dryer 21.

In the embodiment shown in FIG. 1, the combustible gases produced bypyrolyzer 20 are applied to external combustible chamber 12 with whichair heat exchanger 30 is operatively associated. The combustible gasesburn within the external combustion chamber usually in the presence ofexcess air, the heat so produced being transferred via air heatexchanger 30 to the air compressed by compressor 11 before the heatedair is applied to air turbine 13. Heat depleted combustion products exitchamber 12 though line 32 which carries the combustion products to waterheat exchanger 34 of closed Rankine cycle steam power plant 36. Waterheat exchanger 34 vaporizes water and produces steam using heatcontained in the heat depleted combustion products.

Power plant 36 includes steam turbine 38 for expanding the steamproduced by water heat exchanger 34 and driving electric generator 39connected to the turbine. Heat depleted steam exhausted from turbine 38is applied to condenser 40, which is shown as being air cooled in FIG.1, wherein the steam is condensed into condensate which pump 41 returnsto the water heat exchanger to complete the water cycle of the powerplant.

In the embodiment shown in FIG. 1, water heat exchanger 34 includespreheater 42 which is heated by heat depleted expanded air carried byexhaust line 13A of turbine 13. Water heat exchanger 34 also includesboiler 44 (and optionally a superheater associated therewith), whichserves to vaporize (and optionally superheat) the preheated waterfurnished by the preheater. Boiler 44 is heated by heat depletedcombustion products in line 32 produced by external combustion chamber12.

Instead of using air cooled steam condenser 40, the arrangementillustrated in FIG. 1A can be substituted. Specifically, FIG. 1A showssteam condenser 40A as comprising indirect contact heat exchanger 46which contains an organic fluid (such as n-pentane or isopentane,depending on operating conditions) that is vaporized as the steam in thecondenser cools producing vaporized organic fluid in line 47. Thisvaporized fluid is applied to organic vapor turbine 48 within which thevaporized fluid expands driving generator 49 which produces electricity.The turbine exhausts expanded organic vapor into condenser 50, shown asbeing air cooled, wherein condensation takes place producing organicfluid condensate that is returned to condenser 46 by pump 51.

Optionally, some of the combustion air applied to the externalcombustion chamber 12 can be furnished by gas turbine 13 as shown by thebroken lines in FIG. 1. Optionally also, a dust separator can be used asshown by the broken lines in FIG. 1 for extracting small particles fromthe heated and dried oil shale produced by dryer 21.

Alternatively, or in addition, fine particulate and/or dust can beremoved using a suitable filter medium such as classifier apparatus,etc.

In another optional arrangement shown in FIG. 1, some, or all, of theflue gases produced by separator 24 of the gas producing apparatus canbe utilized for generating electricity. If all of the flue gases areused, dryer 21 will not be used, and the raw oil will be supplieddirectly to the pyrolyzer.

Specifically, flue gases produced by separator 24 may be applied toindirect heat exchanger 52 before being vented to the atmosphere. Heatexchanger 52 contains an organic fluid which is vaporized and applied toorganic turbine 53 wherein expansion takes place producing expandedorganic vapor and driving generator 54 which produces electricity. Theexpanded vapor exhausted from turbine 53 is condensed in condenser 55,shown as air cooled, producing organic fluid condensate that pump 56returns to heat exchanger 52.

In a further option in this embodiment, if preferred, heat remaining inheat depleted combustion products produced by external combustionchamber 12 exiting boiler 44 can be utilized, e.g., by producingelectricity using, for instance, an organic Rankine Cycle power plant.In addition, heat remaining in expanded air exhausted from turbine 13exiting preheater 42 can also be utilized, e.g., producing electricityusing, for instance, an organic Rankine cycle power plant. Furthermore,if preferred, alternatively, the heat remaining in expanded airexhausted from turbine 13 exiting preheater 42 can also be utilized, ifthe arrangement shown in FIG. 1A is used, for vaporizing the organicworking fluid in a vaporizer with the vapors being supplied to turbine48. In this case, steam condenser 46 would operate as a preheater forproducing preheated organic fluid condensate supplied to the vaporizerwhich is also furnished with expanded air that exits preheater 42.

In embodiment 36A of the invention shown in FIG. 2, water heat exchanger34A includes preheater 60, vaporizer 61, and superheater 62. Flue gasesfrom air furnace 23 are applied to superheater 62 of the water heatexchanger via line 19A and heat depleted combustion products produced byexternal combustion chamber 12 are applied via line 18A to vaporizer 61.Expanded air exhausted from turbine 13 is applied to preheater 60 vialine 13A.

In operation, water in preheater 60 is preheated by the heat depletedair exhausted from turbine 13 and the preheated water is vaporized invaporizer 61 by indirect contact with the heat depleted combustionproducts in line 18A. The steam produced by vaporizer 61 is superheatedin superheater 62 utilizing the heat contained in the flue gasesproduced by separator 24 associated with line 19A. The superheated steamis applied to steam turbine 38A wherein expansion takes place producingexpanded steam that is applied to condenser 40B containing an organicfluid. The steam condensate produced by condenser 40B is applied todeaerator 66 which is also supplied with steam bled from an intermediatestage of steam turbine 38A. Non-condensable gases contained in the steamseparated in deaerator 66 are extracted. The liquid condensate in thesump of deaerator 66 is returned to preheater 64 by pump 68 completingthe water cycle of the power plant.

As shown in FIG. 2, the organic fluid contained in condenser 40B isvaporized as the steam exhausted from turbine 38 condenses; and thevaporized organic fluid is applied to organic vapor turbine 48Aconnected to generator 49A. Expansion of the organic vapor takes placein the organic turbine causing the generator to produce electricity.Expanded organic vapor is exhausted from the turbine and applied tocondenser 50A, shown as being air cooled, wherein the vapor is condensedto a liquid. The condensate so produced is returned by pump 51A tocondenser 40B for completing the organic fluid cycle.

In this embodiment, if preferred, heat remaining in heat depletedcombustion products produced by external combustion chamber 12 exitingvaporizer 61 can be utilized, e.g., by producing electricity using, forinstance, an organic Rankine cycle power plant. In addition, heatremaining in expanded air exhausted from turbine 13 exiting preheater 60can also be utilized, e.g., by producing electricity using, forinstance, an organic Rankine cycle power plant. Furthermore, ifpreferred, alternatively, the heat remaining in expanded air exhaustedform turbine 13 exiting preheater 60 can also be utilized for vaporizingthe organic working fluid in a vaporizer with the vapors being suppliedto turbine 48A. This optional arrangement is shown in broken lines inFIG. 2. In this case, condenser 40B would operate as a preheater forproducing preheated organic fluid condensate that is supplied to thevaporizer.

In embodiment 36B of the invention shown in FIG. 3, water heat exchanger34B includes preheater 60B and vaporizer 61B. In this embodiment of theinvention, heat depleted combustion products in line 18A at the outputof external combustion chamber 12 are combined with the expanded air inexhaust line 13A of turbine 13 and applied to preheater 60B for thepurpose of preheating water that is supplied to vaporizer 61B. The fluegases from the air furnace of the combustion apparatus in line 19A areapplied to vaporizer 60B producing steam which is applied to turbine 38Ain the manner described in connection FIG. 2. Cooled flue gases exitingthe vaporizer may be treated in a separator for the purpose of removingash from the gases before they are vented to the atmosphere.

In this embodiment, if preferred, heat remaining in the combined flow ofheat depleted combustion products produced by external combustionchamber 12 and expanded air exhausted from turbine 13 exiting preheater60B can be utilized, e.g., by producing electricity using, for instance,an organic Rankine cycle power plant. Furthermore, if preferred,alternatively, the heat remaining in combined flow exiting preheater 60Bcan also be utilized for vaporizing the organic working fluid in avaporizer with the vapors being supplied to turbine 48B. In this case,condenser 40C would operate as a preheater for producing preheatedorganic fluid condensate for supply to the vaporizer.

In embodiment 36C of the invention shown in FIG. 4, water heat exchanger34C includes only vaporizer 61C which is heated in an manner similar tothe manner in which preheater 60B in FIG. 3 is heated. That is to say,the heat depleted combustion products in line 18A from the externalcombustion chamber are combined with expanded air in line 13A connectedto the exhaust turbine 13; and the combined stream is applied tovaporizer 61C for the purpose of vaporizing water contained in thevaporizer. Specifically, vaporizer 61C is designed to raise thetemperature of the water from the temperature of the steam condenser tothe temperature of the steam without using a separate preheater. Steamproduced by vaporizer 61C is applied to steam turbine 38C whereinexpansion takes place producing expanded steam that is condensed incondenser 40C shown as being aircooled. The condensate so produced isreturned by pump 41C to vaporizer 61C.

In embodiment 36C of the invention, the flue gases in line 19A areapplied to a separate, second water heater 34D containing vaporizer 61D.Water in vaporizer 61D is vaporized and applied to steam turbine 38Dwherein expansion takes place producing expanded steam that is appliedto condenser vaporizer 40D in an manner similar to that described inconnection with FIG. 2.

In this embodiment, if preferred, heat remaining in the combined flow ofheat depleted combustion products produced by external combustionchamber 12 and expanded air exhausted from turbine 13 exiting vaporizer61C can be utilized, e.g., by producing electricity using, for instance,an organic Rankine cycle power plant. Furthermore, if preferred,alternatively, the heat remaining in combined flow exiting vaporizer 61Ccan also be utilized for vaporizing the organic working fluid in avaporizer with the vapors being supplied to turbine 48C. In this case,condenser 40C would operate as a preheater for producing preheatedorganic fluid condensate for supply to the vaporizer.

In embodiment 36D of the invention shown in FIG. 5, water heat exchanger34E includes preheater 60E and vaporizer 61E. In this embodiment,preheater 60E is supplied via line 18A with heat depleted combustionproducts from external combustion chamber 12 and vaporizer 61E issupplied via line 19A with flue gases from the air furnace for thepurpose of vaporizing preheated water furnished by preheater 60E. Thesteam produced by vaporizer 61E is applied to steam turbine 38E in thesame manner as described in connection with FIG. 2.

In the embodiment of the invention shown in FIG. 5, expanded air in line13A produced by turbine 13 is fed back to external combustion chamber 12for the purpose of supplying all or part of the air necessary forcombustion in the external combustion chamber.

In this embodiment, if preferred, heat remaining in the heat depletedcombustion products produced by external combustion chamber 12 exitingpreheater 60E can be utilized, e.g., by producing electricity using, forinstance, an organic Rankine cycle power plant. Furthermore, ifpreferred, alternatively, the heat remaining in the flow exitingpreheater 60E can also be utilized for vaporizing the organic workingfluid in a vaporizer with the vapors being supplied to a downstreamturbine. In this case, the condenser associated with steam turbine 38Ewould operate as a preheater for producing preheated organic fluidcondensate for supply to the vaporizer whose heat is derived frompreheater 60E.

Modifications of the compressor-turbine arrangement of FIG. 5 is shownin FIGS. 5A and 5B. In FIG. 5A, compressor 70 represents the compressorof FIG. 5, and is separated into a high pressure stage and a lowpressure stage. Interstage cooling is effected by an intercooler, theheat being rejected into a vaporizer of organic Rankine cycle powerplant 71 having an organic vapor turbine, a condenser shown as being aircooled, and a cycle pump.

In FIG. 5B, interstage cooler 72 extracts heat from air compressed bythe high pressure stage of the compressor, and supplies this heat toambient air which may be supplied to heat exchanger 12 of FIG. 5. Thisarrangement provides heated, excess air to the heat exchanger.

FIG. 6 is an embodiment similar to embodiment 36C of FIG. 4, but theorganic turbine supplied with heat from steam condenser 40D iseliminated, and interstage cooling for compressor 11 is utilized.Specifically, embodiment 36F shown in FIG. 6 includes vaporizer 61F,which is heated by exhaust gases from turbine 13 and heat depletedcombustion products produced by external combustion chamber 12, andserves to vaporize, and preferably superheat, preheated liquid organicfluid. The superheated organic fluid so produced is supplied to organicvapor turbine 75 which drives a generator. Expanded organic vaporexhausted from turbine 75 is condensed in condenser 76, which may be aircooled. The condensate is then pumped into condenser/preheater 40F whichcondenses steam exhausted from steam turbine 38D, and preheats organicfluid condensate produced by condenser 76. The preheated liquid organicfluid is then pumped into vaporizer/superheater 34F to complete theorganic fluid loop. Finally, interstage cooler 77 is associated withcompressor 11 is a part of second organic fluid Rankine cycle powerplant 80 that is similar to the system shown in FIG. 5A.

In power plant 80, organic fluid is vaporized by heat extracted from gasturbine compressor 11 in interstage cooler 77. The organic vaporproduced by cooling interstage cooler 77 is supplied to second organicvapor turbine 78 for also producing power. Expanded organic vapor thatexits turbine 78 is supplied to condenser 79, shown as air cooled, forproducing organic fluid condensate. The organic fluid condensate issupplied by circulation pump 82 to gas turbine intercooler 77 tocomplete this power cycle.

The embodiments described in relation to FIGS. 2 to 6, including FIGS.5A and 5B, show flue gases being supplied by air furnace 23 to watervaporizer via line 19A. These flue gases may include all the flue gasesand remaining fine ash particulate ash or material produced fromseparator 24. In such a case, dryer 21 will not be used and raw oilshale will be directly supplied to the pyrolyzer. Alternatively, theflue gases in line 19A may include only a portion of the flue gases andremaining fine ash particulate ash or material produced from separator24. In such case, the remaining portion of the flue gases is supplied todryer 21 as described in relation to FIG. 1.

Furthermore, while pyrolyzing of oil shale and the use of the gaseousproducts and other products produced by the pyrolyzing of oil shale isspecifically mentioned above as the source of energy for operating thegas turbine and the combined cycle power plant, other fuels and sourcesof heat or energy can also be used in the present invention. Forexample, solar energy, combustion of coal directly or the products ofgasification of coal, fuel oil, heavy fuel oil, land-fill gas, biomass,etc. can be used as the energy or heat source for operating the gasturbine and combined cycle power plant.

Furthermore, the combustion of oil shale, or other substances, togetherwith other materials (e.g., other materials rich in sulfur) such as fuelrich in sulfur (e.g., petroleum coke), or other fuels as described, forexample, in copending U.S. patent applications Ser. Nos. 07/683,690,07/835,358, 07/834,790, 07/834,871, 08/034,887, and 08/078,502 (thedisclosures of which, and the disclosures of their continuations ofwhich, are hereby incorporated by reference) can also be used as theenergy or heat source for the gas turbine and combined cycle powerplant. Moreover, the combustion of oil shale, or oil shale together withother materials (e.g.,other materials rich in sulfur, such as fuels), orother fuels, can be carried out by means other than pyrolyzing (forexample, by using gases produced by the gasification of oil shale). In afurther example, the oil shale or oil shale together with materials suchas fuel can be combusted in a fluidized bed, examples of embodiments ofwhich are shown in FIGS. 7 and 8.

Embodiment 36H shown in FIG. 7 utilizes external combustion chamber 12Ain which solid waste, for example, or other energy sources as shown inthe drawing, is burned in the presence of air, or used, to indirectlyheat compressed air produced by turbogenerator unit 15A. If preferred, afluidized bed combustor can be utilized, or combustible productsproduced by the pyrolysis of oil shale, or oil shale together with othermaterial, e.g., other material rich in sulfur such as sulfur rich fuels,or other fuels as described, for example, in the previously mentionedpatent applications, can be used. The products of combustion produced bychamber 12A are applied to heat exchanger 44A where indirect contactwith water occurs producing steam that is applied to steam turbine 38driving generator 39. The resultant cooled combustion gases are thenvented through a stack (not shown). If suitable, such combustion gasesmay be used to operate a waste heat converter, e.g., an organic Rankinecycle power plant.

Steam exhausted from turbine 38 is condensed in steam condenser 46Awhere liquid organic fluid is indirectly contacted and vaporizedthereby. After the vaporized organic fluid is applied to organic vaporturbine 75A which drives a generator for generating electricity, theexpanded organic vapor exiting turbine 75A is condensed, preferably inan air cooled condenser, and liquid organic fluid is pumped back intosteam condenser 46A to complete the organic fluid cycle.

Second Rankine cycle organic fluid power plant 80A is also a part ofthis embodiment. In power plant 80A, organic fluid is vaporized by heatextracted from gas turbine compressor 11 in interstage cooler 77A. Theorganic vapor produced by cooling interstage cooler 77A is supplied tosecond organic vapor turbine 78A for also producing power. Expandedorganic vapor that exits turbine 78A is supplied to condenser 76A, shownas air cooled, for producing organic fluid condensate. The organic fluidcondensate is supplied by circulation pump 82A to gas turbineintercooler 77A to complete this power cycle.

In embodiment 36I shown in FIG. 8, turbogenerator 100 is a conventionalgas turbine based arrangement in which turbine 101 drives generator 102and compressor 103 having low pressure stage LP and high pressure stageHP. Interstage cooler 104 extracts heat from the air produced by the LPstage and vaporizes an organic fluid. The cooled air that exits from theinterstage cooler is further compressed by the HP stage of thecompressor and is supplied to combustor 105 where fuel is burned toproduce hot combustion gases that are applied to gas turbine 101. Hotgases exhausted from this turbine are directed to external combustionchamber 106 wherein solid waste fuel, for example, is combustedproducing hot products of combustion. Alternatively, other energysources can be used including, but not limited to, solar energy,biomass, oil shale, oil shale together with materials such as othersulfur rich materials, or combustible products produced by the pyrolysisof oil shale, or oil shale together with other material, e.g., othermaterial rich in sulfur such as sulfur rich fuels, or other fuels asdescribed, for example, in the previously mentioned patent applications,can be used. If preferred, a fluidized bed combustor can be used.Furthermore, other energy sources, such as those listed in FIGS. 7 and8, also can be used.

Heat in the hot products of combustion is indirectly transferred tocompressed air produced by compressor 107 of turbogenerator 108 which isan air turbine based arrangement. Compressor 107 includes low pressurestage LP that produces compressed air that is cooled in interstagecooler 109 that serves to vaporize organic fluid.

The cooled air that exits interstage cooler 109 is further compressed bythe HP stage of the compressor and is supplied to external combustionchamber 106 wherein the high pressure air produced by the HP stage ofcompressor 107 is indirectly heated and supplied to air turbine 110 thatdrives electric generator 111. The products of combustion produced bychamber 106 are applied to heat exchanger 44B where indirect contactwith water occurs producing steam that is applied to steam turbine 38driving electric generator 39. The resultant cooled combustion gases arethen vented through a stack (not shown). If suitable, the combustiongases can be used to operate a waste heat converter, e.g., an organicRankine cycle power plant. Finally, steam condensate produced in heatexchanger 116 by condensing expanded steam exiting steam turbine 38, ispumped back into vaporizer 44B completing the water cycle.

Vaporized organic fluid produced by intercoolers 104 and 109 is suppliedto first organic vapor turbine 112 that drives electric generator 113.Expanded organic vapor that is exhausted from turbine 112 is condensedin condenser 114, preferably air cooled. The resultant condensate ispumped back to both intercoolers 104 and 109 to complete the firstorganic fluid cycle.

Air exhausted from air turbine 110 is supplied to heat exchanger 115which vaporizes liquid organic fluid that had been preheated in steamcondenser 116 within which steam exhausted from steam turbine 38 iscondensed. Vaporized organic fluid produced by heat exchanger 115 isapplied to second organic vapor turbine 117 that drives generator 118.Expanded organic vapor exhausted from turbine 117 is condensed,preferably in air cooled condenser 118, and pumped back to heatexchanger 116 completing the second organic fluid cycle.

Furthermore, since in the present invention, the gas turbine used isoperated by heated air which is supplied to the inlet of the gas turbinewithout the direct contact of fuel and combustion products, the use ofaeroderivative gas turbines is possible and is preferred.

The embodiments described in relation to FIGS. 5A, 6, 7 and 8 employseparate organic fluid power cycles for utilizing heat extracted fromthe intercoolers of the compressors associated with the gas turbines. Ifpreferred, however, an alternative single dual pressure organic powercycle like that shown in FIG. 9 can be used. In this case, a singleorganic condenser 114A, shown as being air cooled, is used. As shown,single electric generator 137 driven by steam turbine 138, and by lowpressure organic fluid turbine 112A and high pressure organic fluidturbine 117A, can be used for producing electricity. Alternatively,separate electric generators may be used.

If preferred, instead of using separate low pressure organic fluidturbine 117A and high pressure organic fluid turbine 112A, low pressureorganic fluid can be injected at an intermediate stage of an organicvapor turbine to which high pressure organic fluid is supplied fromintercooler 104A as shown in FIG. 9A. Valve 120 is controlled bytemperature sensor 122 provided for sensing the temperature of the fluidexiting the steam condensate side of the steam condenser. Thus, valve120 operates to ensure that sufficient organic fluid condensate issupplied to steam condenser 116A by feed pump 124 so that thetemperature of the fluid exiting the steam condensate side of steamcondenser 116A is such that steam condensate is always produced.

Alternatively, if preferred, instead of using steam turbine 128 inconjunction with low pressure organic vapor turbine 117A, a singleorganic Rankine cycle turbine can be used operating on the exhaust gasesof gas turbine 131 and having an air or water cooled condenser. In astill further alternative, in the embodiment described in relation toFIG. 9, two separate organic vapor condensers can be used instead ofsingle condenser 114 thus permitting two separate organic Rankine powercycles to be used.

Furthermore, even though in the previously described embodiments of thepresent invention, an external combustion chamber is used, the system ofthe present embodiment is also very advantageous when a gas turbine andsteam turbine are used together in a combined cycle power plant wherethe gas turbine is not externally fired, but rather run by gas, such asnatural gas, etc., or other suitable fuel, e.g., kerosene, etc. forcombusting in combustion chamber 105A of the gas turbine to directlyheat the compressed air exiting compressor 103A of gas turbine 130 alsoas shown in FIG. 9.

Additionally, the use of an organic Rankine cycle power plant utilizingheat extracted from the intercooler of a gas turbine similar inprinciple to that shown in FIG. 9 is also very advantageous even whenthe gas turbine is used solely for supplying power during peak electricdemand and is not part of a combined cycle power plant. Thus, accordingto a further embodiment of the present invention (shown by thecomponents enclosed by the dashed lines in FIG. 9), an organic Rankinecycle power plant utilizing heat extracted from the intercooler of a gasturbine can be used for producing power in a manner similar to thatshown in the gas turbine portion of FIG. 9. In this embodiment as well,the combustion chamber of the gas turbine can be an external combustionchamber, or run by gas, such as natural gas, etc., or other suitablefuel, e.g., kerosene, etc. for directly heating the compressed gasexiting the compressor of the gas turbine.

Furthermore, when oil shale or other solid fuel or material is used inthe present invention, its feeding rate can be controlled according tothe present invention by a parameter of the power plant, such as theexit temperature of the external combustion chamber. Such temperaturemay be measured by a temperature sensor, such as sensor 31 shown, forexample, at the exit of external combustion chamber 12 in FIG. 1, etc.

The advantages and improved results furnished by the method andapparatus of the present invention are apparent from the foregoingdescription of the preferred embodiment of the invention. Variouschanges and modifications may be made without departing from the spiritand scope of the invention as described in the appended claims.

We claim:
 1. A gas turbine power plant system of the type having acompressor which compresses ambient air, a heater which heats thecompressed air and produces heated gas, a turbine which expands theheated and compressed gas producing power and expanded gas, said systemcomprising: a) combustible products producing apparatus which producescombustible products that include combustible gases; b) a closed organicRankine cycle power plant having a heat exchange system including avaporizer which vaporizes an organic working fluid and produces anorganic working fluid vapor using heat contained in said expanded gas,an organic vapor turbine which expands the organic working fluid vaporand produces power and expanded organic working fluid vapor, an organicfluid condenser which condenses the expanded organic working fluid vaporand produces organic working fluid condensate whereby the organicworking fluid condensate is returned to the vaporizer; and c) a thermalwater fluid cycle containing water fluid which produces heated waterfluid, the heat contained in the heated water fluid being transferred tosaid organic working fluid condensate via said heat exchange system. 2.A gas turbine power plant system according to claim 1 wherein heatcontained in said expanded gas is transferred to said water fluidcontained in said thermal water fluid cycle which produces heated waterfluid and the heat contained in the heated water fluid is transferred tosaid organic working fluid condensate present in said heat exchangersystem from which organic working fluid vapor is produced which issupplied to said organic vapor turbine which produces power.
 3. A gasturbine power plant system according to claim 1 wherein said thermalwater fluid cycle comprises a closed Rankine cycle power plant having awater heat exchanger which vaporizes water and produces steam using heatcontained in said expanded gas, a steam turbine which expands the steamproducing power and expanded steam, and a steam condenser whichcondenses the expanded steam and produces steam condensate and means forreturning the steam condensate to the water heat exchanger.
 4. A gasturbine power plant system according to claim 3 wherein the steamcondenser is cooled by organic fluid and produces organic working fluidvapor which is supplied to said organic vapor turbine.
 5. A gas turbinepower plant system according to claim 3 wherein the steam condenser iscooled by organic fluid and produces pre-heated organic working fluidwhich is supplied to a vaporizer which produces organic working fluidwhich is supplied to said organic vapor turbine.
 6. A gas turbine powerplant system according to claim 1 wherein said heat exchanger systemincludes a pre-heater which pre-heats said organic working fluid.
 7. Agas turbine power plant system according to claim 2 wherein said heatexchanger system includes said vaporizer which produces said organicworking fluid vapor which is supplied to said organic vapor turbine thatdrives a generator and produces electricity.
 8. A gas turbine powerplant system according to claim 1 wherein said vaporizer includes asuperheater which superheats said organic working fluid.
 9. A gasturbine power plant system according to claim 8 wherein said heatexchanger system includes a pre-heater which pre-heats said organicworking fluid.
 10. A gas turbine power plant system according to claim 1wherein said combustible gases are combusted in said heater which heatssaid compressed air.
 11. A gas turbine power plant system according toclaim 10 wherein said combustible gases which are combusted in saidheater which heats said compressed air comprise natural gas.
 12. A gasturbine power plant system according to claim 10 wherein saidcombustible gases which are combusted in said heater are combusted in anexternal combustion chamber.
 13. A gas turbine power plant systemaccording to claim 1 wherein said combustible products producingapparatus which produces combustible gases comprises a pyrolyzer whichproduces combustible gases from oil shale.
 14. A gas turbine power plantsystem according to claim 1 wherein said combustible products producingapparatus which produces combustible gases comprises apparatus whichproduces combustible gases from oil shale.
 15. A gas turbine power plantsystem according to claim 1 wherein said combustible products producingapparatus which produces combustible gases comprises apparatus whichproduces combustible gases from oil shale and sulfur rich fuel.
 16. Agas turbine power plant system according to claim 15 wherein saidcombustible gases which are combusted in said heater are combusted in anexternal combustion chamber.
 17. A gas turbine power plant systemaccording to claim 15 wherein said sulfur rich fuel is heavy fuel oil.18. A gas turbine power plant system according to claim 1 wherein saidorganic working fluid is n-pentane.
 19. A gas turbine power plant systemaccording to claim 1 wherein said organic working fluid is isopentane.20. A method for producing power using a gas turbine power plant systemof the type having a compressor that compresses ambient air, a heaterwhich heats the compressed air and produces heated gas, a turbine thatexpands the heated and compressed gas producing expanded gas and power,said method comprising: a) producing combustible products includingcombustible gases using combustible products producing apparatus; b)producing power using a closed organic Rankine cycle power plant havinga heat exchanger system including a vaporizer that vaporizes an organicworking fluid and produces an organic working fluid vapor, an organicworking fluid vapor turbine that expands the organic working fluid vaporand produces power and expanded organic working fluid vapor, an organicfluid condenser that condenses the expanded organic working fluid andproduces organic working fluid condensate whereby the organic workingfluid condensate is returned to the vaporizer; and c) transferring heatcontained in heated water fluid in a thermal water fluid cycle to saidorganic working fluid condensate via said heat exchanger system.
 21. Amethod according to claim 20 including transferring heat contained insaid expanded gas to said water fluid contained in said thermal waterfluid cycle that produces heated water fluid, the heat contained in theheated water fluid being transferred to said organic working fluidcondensate present in said heat exchanger system from which organicworking fluid vapor is produced that is supplied to said vapor tubinewhich produces power.
 22. A method according to claim 20 includingvaporizing water in a water heat exchanger contained in said thermalwater fluid cycle and producing steam using heat contained in saidexpanded gas, expanding the steam in a steam turbine producing power andexpanded steam, and condensing said expanded steam in a steam condenserand producing steam condensate which is returned to the water heatexchanger.
 23. A method according to claim 22 including cooling thesteam condenser by organic fluid and producing organic working fluidvapor that is supplied to said organic vapor turbine.
 24. A methodaccording to claim 22 including cooling the steam condenser by organicfluid and producing pre-heated organic working fluid that is supplied toa vaporizer that produces organic working fluid vapor that is suppliedto said organic vapor turbine.
 25. A method according to claim 20including pre-heating said organic working fluid using a pre-heatercontained in said heat exchanger system.
 26. A method according to claim21 including vaporizing said organic working fluid using a vaporizercontained in said heat exchanger system that produces said organicworking fluid vapor that is supplied to said organic vapor turbine thatdrives a generator and produces electricity.
 27. A method according toclaim 20 including superheating said organic working fluid.
 28. A methodaccording to claim 27 including pre-heating said organic working fluidusing a pre-heater contained in said heat exchanger system.
 29. A methodaccording to claim 20 including combusting said combustible gases insaid heater that heats said compressed air.
 30. A method according toclaim 29 including combusting natural gas in said heater that heats saidcompressed air.
 31. A method according to claim 29 including combustingcombustible gases in an external combustion chamber.
 32. A methodaccording to claim 20 including pyrolyzing solid fuel in a pyrolyzerthat is part of said combustible products producing apparatus thatproduces combustible gases.
 33. A method according to claim 32 includingpyrolyzing oil shale in a pyrolyzer that is part of said combustibleproducts producing apparatus that produces combustible gases.
 34. Amethod according to claim 20 including producing combustible gases usingsaid combustible products producing apparatus from solid fuel and sulfurrich fuel.
 35. A method according to claim 34 including producingcombustible gases using said combustible products producing apparatusfrom oil shale and sulfur rich fuel.
 36. A method according to claim 34including combusting said combustible gases in an external combustionchamber.
 37. A method according to claim 34 including producingcombustible gases using said combustible products producing apparatusfrom solid fuel and heavy fuel oil.
 38. A method according to claim 20including producing power using a closed organic Rankine cycle powerplant using n-pentane as the organic working fluid.
 39. A methodaccording to claim 20 including producing power using a closed organicRankine cycle power plant using isopentane as the organic working fluid.